This invention relates to a passing person counting apparatus installed at places where counting of the number of persons or passengers coming and going passing therethrough is constantly required, such as entrances or steps of transportation means, for example, automobiles, ships, trains, or airplanes, of public houses, for example, banks, department stores, shops, museums, theaters, office buildings, or of public facilities, for example, zoos, juvenile parks, recreation grounds, etc.
Taking up a case of a sight-seeing bus, it was a traditional common way of counting or ascertaining the number of passengers or group members thereon to count it by means of visual direct counting one by one, roll calling. And in particular, when some of or all of the members get out of the vehicle on the way for sight-seeing or taking a rest, a person who is responsible for counting the number of the members, such as a driver, a conductor, a guide had to repeat a trouble of confirming the number, often by means of requesting the members themselves to ascertain the getting on board or coming back to the seat of the neighboring member. Such a way of counting or ascertaining the number was not only irrational but also inaccurate to cause sometimes a shortage of embarkation of the members. This tendency is also true with cases of trains, ships, or airplanes.